Air and water control mechanism



NGV 3, 1942. A. H. KATTl-:RJOHNA AIR AND WATER CONTROL MECHANISM 2 Sheets-sheet l Filed July 6. 1940 i y INVENTOR I 705/ /7 /ff/g/o.

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:wmv w \/v/ Il 1 BY- m WTTORNEY NOV- 3, 1942-A A. H. KATTERJOHN 2,300,932

AIR AND WATER CONTROL MECHANISM Filed July 6, 1940 2 Sheets-Sheet 2 BY WTTRNEY Patented Nov. 3 1942 Am AND WATER coN'rnoL MECHANTSM August H. Katterjohn, Detroit, Mich., assignor to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey Application July 6, 1940, 'Serial' N0. 344,224

Claims.

This invention relates generally to the operating controls of a percussive tool and more particularly to van improved combination air and water throttle control mechanism for use in rock drills and like tools.

The practice of spotting or starting `a drill hole without first splashing the surface of the rock with water is largely responsible for the excessive dust conditions frequently found in mines and other confined working areas. So long as rock drills are constructed with independent throttle valves for the air `and water connections, it is possible for operators to follow this practice of dry spotting and they frequently do so in `preference to the time consuming routine of operating separate valves in a set sequence. Some effort has been made to place the air valve and water valve under the control of a single operating lever and the prior art gives a few instances of combined controls in which the separatevalves can only be opened in the desired sequence. All such constructions necessitate an operating connection between the valves and this fact has presented a new problem in that an exchange of air land water, by seepage between the respective fluid inlets, is permitted. The entrance of water into the passages of the compressed air distributing system may cause corrosion and seriously interfere with moving parts within the tool and a construction permitting such an occurrence is therefore undesirable.

This.invention presents a combined 'air and water throttle control mechanism that improves upon prior art structures through the provision of a bellows which acts as a positive seal between the air and water inlets and performs the additional function of transmitting motion from the air valve to the water Valve.

One object of the invention is to eliminate the possibility of air and water seepage along` an operating connection intermediate air and water valves.

Another object of the invention is to seal air and water inlets from each other by a fluid tight means including a bellows.

A further object of the invention is to seal air and Water inlets from each other by a iiuid tight means capable of transmitting motion.

Other objects and structural details of the invention will be more apparent from the following description when read in conjunction with the accompanying drawings, wherein:

Fig. 1 is a longitudinal section of the rear portion of a rock drill embodying the mechanism the front end of the drill. The piston of the invention, taken through the broken line l-l in Fig. 2;

Fig. 2 is a rear end View of the tool shown in Fig. .1;

Fig. 3 is a fragmentary View taken along the line 3--3 of Fig. 2 showing the air throttle valve in open position;

Fig. 4 is a view in cross-section of the water valve assembly and is taken along the line lt-t of Fig. 1; and

Fig. 5 is a detail view, partly in section., of the bellows.

The air and water throttle control is illustrated in Fig. l in operative relation to a distributing valve and water tube of conventional types. The illustrative drill includes a backhead l0 in which the throttle control mechanism is mounted, a barrel Il, secured to the backhead i0, and having a piston chamber i2 formed therein, and a hammer piston I3 reciprocable within the chamber l2 to deliver blows of percussion to a working implement (not shown) mounted at I3 is slidably mounted on a riiie bar Hl which is caused, by means including a ratchet ring l5, to move in a step-by-step rotary movement, which movement is imparted to the piston i3 through a nut I6 fixed within the piston and engaging the helical splines formed on the rifle bar. The

reciprocating movement of the piston i3 is effected by compressed air admitted to the tool under the control of an air throttle valve il' and directed by a distributing valve assembly H3 to alternate ends of the chamber i2. The valve assembly l, comprising generally a casing i9, a bushing 2l and reciprocable cylindrical valve 22, is positioned within the barrel il and encircles the shank of the rifle bar I4.

Referring also to Figs. 2 and 3, it will be seen that the air throttle valve Il is generally tubular in shape and is positioned in a bore 23 extending transversely through the upper front end of the backhead HJ. A compressed air conducting hose line `2li (Fig. 2) extends into one end of the bore 23 and air flowing into the bore passes into a chamber 25 (Figs. 1 and 3) formed within the valve l1 throughout a portion of its length. The left hand end of the valve il, as viewed in Fig. 2, is reduced to form an extension lla which projects outside the bore 23 yand has secured thereto a manually operable lever 26 by which the valve may be oscillated to place a port 21 (Fig. 3) therein, into and out of registry with an air passage 28. With the valve Il positioned as shown in Fig. 3 air flowing into the chamber 25 is permitted to pass out the port 21 to passage 23 and is then conducted around an annular groove 29 and through a port 3l, in ratchet ring I5, to the ports and passages of the distributing valve assembly I8. Upon movement of the throttle valve I'I to the position shown in Fig. l the port 21 is placed out of registry with the passage 28 to prevent the flow of air from chamber 25 and thereby stop operation of the drill.

As shown in Fig. 1, the means for conducting Water through the tool for use as a cleansing fluid comprises a centrally positioned water tube 32 leading from the backhead I0 through the rifle bar I4 and hammer piston I3 to the front end of the toll. Water, under moderate pressure, is directed through the tube 32 and .forced through a longitudinal passage in the drill steel to wash out the cut material, or detritus, from the drill hole and allay dust. The rear end of the tube 32 extends into a bore 33 in the back- H head I to which water is directed through a passage 34. The bore 33 is closed bya plug 35 which, in cooperation with a spacing ring 36 and resilient cushion 31, encloses the adjacent end of the water tube. The spacing ring 36 and cushion 31 are positioned between a ange 38 on the tube 32 and the inner end of the bore 33, while the inner end of the plug 35 engages the spacing ring 36 and is formed with a recess 39 receiving the flange 38. The inner end of plug 35 is reduced to permit the flow of water from the passage 34 into the bore 33, and communication is established between the area surrounding the reduced portion of the plug 35 and recess 39 by a set of transverse ports 4I and a longitudinal passage 42, inthe plug.

Considering now the water inlet and means for controlling the flow of water to the passage 34 and bore 33, the water enters the drill through a bore 43, in backhead I5, to which it is conducted by a hose line 44 (Fig. 2). From bore 43, the water passes through a passage 45 to another bore 43 with which the passage 34 also communicates. The bore 46 is closed by a cap 41 `and positioned within the bore is a bushing 48 having an annular groove 49 registering with the passage 45. A set of ports I connect the groove 49 to a recess 52 in the outer end of the bushing 48, and a central passage 53 connects the recess 52 to an oppositely disposed recess 54 in the inner end of the bushing. The inner recess 54 communicates with the passage 34 through a set of ports 55 and an annular groove 55 formed in the bore 46. The flow of water from bore 43 to the recess, or inlet chamber, 52 is unrestricted but a valve 5l' movable to open and closed positions with respect to the central passage 53 controls the flow from outer recess 52 to inner recess 54. A spring 53, interposed between the cap 4l and valve 5l presses the valve to the position illustrated, in which communication between the recesses 52 and 54 is cut off and the passage of water to the tube 32 is prevented. In order that the valve 51 may be moved off its seat in the outer end of passage 53 to open position it is provided with a stem 59 extending through the passage 53 into the recess 54, in alignment with an actuating plunger 6I.

The plunger 6I is movable within a bushing 62 supported at the inner end of the bore 46 and extending partly within a passage 63 connecting bore 45 and the air inlet bore 23. The inner end'of the plunger 6I projects into the bore 23 in cooperative relation with a flange 64 formed on the right hand end (Fig. v2) ofthe throttle valve Il. The flange 64 occupies only a portion of the circumference of the valve I'I and its opposite ends are formed as inclined cam surfaces (Fig. l). One of the cam surfaces 65 is positioned adjacent the plunger and is adapted, upon rotation of the throttle valve, to engage the plunger and move it leftward to unseat valve 5l' As shown in Fig. 1, in the normal, or closed, position of the throttle valve I'I, the cam surface 65 adjacent the plunger 6I is located immediately above the inner end of the plunger. Thus, at the very start of the counterclockwise movement of the throttle valve to open position the plunger 5I is cammed outward and the valve 5l is opened to admit water to the tube 32 before port 2l' is brought to registry with the passage 23 to initiate operation of the hammer piston. When the throttle valve Il is restored to closed position the spring 58 is permitted to return the valve 5'! and plunger 6I to the normal position of Fig. 1. In order that the valve 51 may be guided within the passage 53, the stem 59 of the valve is formed with a plurality of ribs 59a. (see also Fig, 4) engageable with the wall of the passage and spaced apart to permit the free flow of water from recess 52 to recess 54.

The mechanism described above, whereby the air throttle valve and the water valve are placed under the control of a common operating means, simplifies operation of the tool and presents another advantage in that it makes it impossible for the operator to begin drilling without first spraying the Work with a stream of Water. Such a construction presents a problem, however, since, with the tool in constant use, water from the recess 54 tends to seep along the plunger 6I into the bore 23 and to be blown into the air passages of the valve assembly I3, This diiiiculty, present in prior art structures of this class, is overcome by the present invention through the provision of a metallic bellows 66 (see also Fig. 5) which encloses the portion of bushing 62 and that end of the plunger 6I which extend into the recess 54. The base 61 of bellows 56 flares outward and is secured between the inner end of the bushing 48 and a flange 68 formed on the bushing 62. The outer end of the bellows is closed by a disc 69 pressed into a fluid tight engagement with the end surface of the bellows. The valve stem 59 and plunger GI engage the disc 69 on opposite sides thereof and eiect movement of each other through compression andexpansion of the bellows relatively to its fixed base 61, The manner in which the base 61 of the bellows is clamped between the bushings 48 and 62 renders this connection fluid tight. Air, seeping into the bellows 66 along the lplunger BI, may ind its way to the atmosphere through a port 'II and groove I2, in bushing 52, opening into an exhaust passage 13.

Although the bellows 63 is preferably constructed of metal, other materials may be used in its construction without departure from the present invention- What is claimed is:

1. In a device of the class described, the cornbination of a main air inlet, a first valve settable to closed and open positions to prevent and permit the flow of air from said main air inlet, a water inlet to which water under pressure is directed for use as a -cleansing fluid, a second valve settable to closed and open positions to prevent and permit the flow .of water from said water inlet, a plunger controlled by movement of said first valve and extending from said air inlet into cooperative relation with said second valve, and a bellows transmitting the movement of said plunger to said second valve and acting as a seal between the air and water inlets.

2. In aldevice of the class describedpthe combination of a main air inlet, a rst valve settable to closed and open positions to prevent and permit the flow of air from said main air inlet, a water inlet to which water under pressure is directed for use as a. cleansing fluid, a second valve settable to closed and open positions to prevent and permit the flow of Water from said water inlet, a plunger controlled by movement of said first valve and extending from said air inlet into cooperative relation with said second valve, and a bellows positioned between said plunger and said second Valve to cut off communication between said water inlet and said'air inlet and engaged on one side by said plunger and on the other side by said second Valve to transmit. the movement of each of said elements to the other.

3. In a device of the class described, the combination of a main air inlet, a rst valve settable to closed and open positions to prevent and permit the ow of air from said main air inlet, a water inlet to which water under pressure is directed for use as a cleansing fluid, a second valve settable to closed and open po-sitions to prevent and permit the flow of water from Said water inlet, a plunger extending between said air inlet and said water inlet and disposed with its opposite ends in cooperative relation respectively with said first valve and said second valve, a cam surface on said first valve arranged to actuate said plunger upon movement of saidiirst valve toward open position, and a bellows enclosing one end of said plunger to prevent the passage of water and air to and from said main air inlet around said plunger, said bellows acting in cooperation with said plunger to transmit the movement of said first valve to said second valve.

4. In a device of the class described, the cornbination of a main air inlet, a first valve settable to closed and open positions to prevent and permit the flow of air from said main air inlet, a water inlet to which water under pressure is directed for use as a cleansing iluid, a passageway leading from said water inlet through which water is directed from said water inlet, a `second valve positioned in said passageway and settable to closed and open positions to prevent and permit the flow of water through said passageway, a valve actuating plunger having one end extending into said passageway adjacent said second valve and having its opposite end extending into said main air inlet adjacent said first valve, a cam surface on said first valve arranged to actuate said plunger upon movement of said first valve toward open position, and a bellows enclosing that end of said plunger which extends into said passageway to prevent the passage of water and air to and from said main air inlet around said plunger, said bellows acting in cooperation with said plunger to transmit the movement of said rst valve to said second valve.

5. In a device of the class described having separate air and water inlets, the combination of a throttle valve within said air inlet and movable to closed and open positions to prevent and permit the flow of air therefrom, a bushing positioned in said water inlet and having a rearwardly facing recess and a forwardly facing recess, a central passage in said bushing connecting said rearwardly and forwardly facing recesses, a control valve movable to closed and open positions with respect to said central passage to prevent and permit the passage of water from one to another of said recesses, a valve actuating plunger having one end extending into one of said recesses adjacent said control valve and having its opposite end extending into said air inlet adjacent said throttle valve, a cam surface on said throttle valve arranged to actuate said plunger upon movement of said throttle valve toward open position, and a bellows enclosing that end of said plunger which is adjacent said control valve to prevent the passage of water and air to and from said air inlet around said plunger, said bellows acting in cooperation with said plunger to transmit the movement of said throttle valve to said control Valve.

AUGUST H. KAT'IERJOHN. 

